Search results for "Neurofibromin 1"
showing 5 items of 5 documents
Diagnostic and prognostic value of CD10 in peripheral nerve sheath tumors
2009
Background: Neurofibromas are sporadic or associated with type 1 neurofibromatosis (NF1), with a higher risk of malignant progression. Materials and Methods: We investigated CD10 immunoexpression in 39 peripheral nerve sheath lesions. They were 18 typical, solitary, sporadic neurofibromas (group A) and 21 cases (group B) consisting of 11 NF1-associated cases, 3 malignant peripheral sheath tumors (MPNST) and 8 atypical neurofibromas. Results: CD10 immunopositivity was absent or very weak and focal in group A. On the contrary, CD10 was strongly expressed in group B, including all the MPNST and their metastases, with 95% sensitivity and 72% specificity in distinguishing between the two groups.…
Mutation spectrum of NF1 gene in Italian patients with neurofibromatosis type 1 using Ion Torrent PGM™ platform
2017
Neurofibromatosis type 1 (NF1) is caused by mutations of the NF1 gene and is one of the most common human autosomal dominant disorders. The patient shows different signs on the skin and other organs from early childhood. The best known are six or more café au lait spots, axillary or inguinal freckling, increased risk of developing benign nerve sheath tumours and plexiform neurofibromas. Mutation detection is complex, due to the large gene size, the large variety of mutations and the presence of pseudogenes. Using Ion Torrent PGM⢠Platform, 73 mutations were identified in 79 NF1 Italian patients, 51% of which turned out to be novel mutations. Pathogenic status of each variant was classifi…
One
2019
Neurofibromatosis type 1 (NF1) is an autosomal dominant disease with complete penetrance but high variable expressivity. NF1 is caused by loss-of-function mutations in the NF1 gene, a negative regulator of the RAS-MAPK pathway. The NF1 gene has one of the highest mutation rates in human disorders, which may explain the outbreak of independent de novo variants in the same family. Here, we report the co-occurrence of pathogenic variants in the NF1 and SPRED1 genes in six families with NF1 and Legius syndrome, using next-generation sequencing. In five of these families, we observed the co-occurrence of two independent NF1 variants. All NF1 variants were classified as pathogenic, according to t…
Absence of mutation at the GAP-related domain of the neurofibromatosis type 1 gene in sporadic neurofibrosarcomas and other bone and soft tissue sarc…
1995
The NF1 gene encodes neurofibromin, a GTPase-activating protein containing a GAP-related domain (NF1-GRD) that is capable of downregulating ras by stimulating ras intrinsic GTPase activity. We tested 44 sarcomas, nine of which corresponded to sporadic neurofibrosarcomas, for mutations at the NF1-GRD by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, finding no mutation in every sample tested. We suggest that inactivation of the NF1-GRD by gene mutation seems not to be an important event in the tumorigenesis of sarcomas.
SPRED1, a RAS MAPK pathway inhibitor that causes Legius syndrome, is a tumour suppressor downregulated in paediatric acute myeloblastic leukaemia
2013
Constitutional dominant loss-of-function mutations in the SPRED1 gene cause a rare phenotype referred as neurofibromatosis type 1 (NF1)-like syndrome or Legius syndrome, consisted of multiple café-au-lait macules, axillary freckling, learning disabilities and macrocephaly. SPRED1 is a negative regulator of the RAS MAPK pathway and can interact with neurofibromin, the NF1 gene product. Individuals with NF1 have a higher risk of haematological malignancies. SPRED1 is highly expressed in haematopoietic cells and negatively regulates haematopoiesis. SPRED1 seemed to be a good candidate for leukaemia predisposition or transformation. We performed SPRED1 mutation screening and expression status i…